Interior corrosion in pipelines, containers and processing facilities is a serious issue that jeopardizes a safe, reliable and environmentally harmless operation of industrial processes. Most metallic materials are very vulnerable to contact with water and a variety of electrolytes. This is a particularly serious problem in the oil industry, due to the growing total salinity and acidity of primary production, which has an impact in the entire chain of transport, refining and distribution processes.
Interior corrosion in pipelines, containers and industrial facilities caused by transport, storage or processing of fluids that contain water and electrolytes can be controlled using corrosion inhibitors.
The process of adding corrosion inhibitors to hydrocarbons being transported, stored or processed has proven significantly successful in mitigating corrosion to levels below two thousands of an inch per year, a parameter that is a requirement for many regulations to ensure several decades of useful life for metallic components (Norm NRF-005-PEMEX-2009). There's a wide variety of products that serve as corrosion inhibitors, one of the most important ones is the family of compounds known as imidazolines, which inhibit corrosion in low dosages from 5 to 150 ppm, and are considered amongst the most environmental friendly substances used in the industry. 2-Alkyl-imidazolines have been used as corrosion inhibitors in the oil industry since the 1940's. These inhibitors are used as mixtures of imidazolines with a hydrocarbonated chain of 7 to 19 carbon atoms (hydrophobic group) in position two, and a polar group in position one, such as hydroxyethyl or acylaminoethyl. Imidazolines can also be quaternized to be employed as cationic surfactants, fabric softeners, hair conditioners or antistatics.
Imidazolines of the 2-(2-alkyl-4,5-dihydro-1H-imidazol-1-il)ethanol type, extracted from vegetable oils such as palm or coconut oil, or animal fats, are commercially traded for different applications. An important usage for this type of compounds is corrosion inhibition for pipelines, containers and other facilities, property of industries that transport, process and store hydrocarbons. However, obtaining or applying imidazolines derived from oils extracted from coffee waste has never been conceived before. Even when coffee oil is well-known as a source of biofuels, no other process has been reported to obtain imidazolines derived from coffee oil. Coffee waste resulting from residue left over from the preparation of coffee beverages and other coffee based products, contain between 13 and 15% (dry base) of oil, which includes linoleic acid as the most abundant fatty acid found in this oil. Linoleic acid is doubly unsaturated, conferring the imidazolines containing it a superior adherence to metallic surfaces, due to the interaction of the pi electrons of the double bonds with the electrons of the metallic surface.
Imidazolines derived from coffee oil show, besides excellent qualities as corrosion inhibitors, low toxicity and good biodegradability, which makes them a very appropriate and environmentally friendly option as corrosion inhibitors for the industry as well as being suitable for applications such as fabric softeners, antistatic agents, hair conditioners, etc.
Coffee is one of the most important agricultural products worldwide and is also one of the most popular beverages with a very high level of consumption. It is estimated that worldwide, coffee production is close to 6 million tons, with ten leading countries. Coffee consumption is varied, from 12 Kg per capita in Finland, to a general average of 1.2 kg per capita. Depending on variety, the content of oil in coffee waste fluctuates between 13-18% (dry base). Most of ground coffee bean residue is disposed of in landfills, even though it has been proposed to use it to produce compost. Coffee waste is known as a soil and water bank pollutant, due to the toxic properties of caffeine.
Coffee oil is a mixture of triglycerides constituted by fatty acids of 14 to 22 carbon atoms, with a composition of fatty acids that depends on the type and origin of the coffee. It has been reported a composition of 44% linoleic acid, 33% palmitic acid, 9% oleic acid, 7% stearic acid and other fatty acids in minor contents.
Several processes have been described for coffee oil extraction, as a starting material for biodiesel. These processes employ soxhlet equipment, supercritical CO2 for dry coffee waste, as well as ultrasound assisted biphasic extraction.
The procedures mentioned above for extraction of oil from coffee are, from our point of view, not feasible on an industrial scale, given that they require coffee that has been previously dried, as well as very costly industrial equipment, such as those that would demand the use of ultrasound or supercritical CO2.
Specialized literature shows relevant references on the history and scientific breakthroughs that support this invention: Ortega-Toledo, D. M.; Gonzalez-Rodriguez, J. G.; Casales, M.; Martinez-Gomez, L. Corrosion Science, 53, 3780-3787 (2011); Radcriffe, R. U.S. Pat. No. 2,200,815 (1940); Meyer, G. R., U.S. Pat. No. 6,448,411 (2002); Daglia, M; Racchi, M.; Papetti, A.; Lanni, C.; Govoni, S.; Gazzani, G. Journal of Agricultural and Food Chemistry, 52, 1700-1704 (2004); Barkenbus, C.; Zimmerman, A. J. Journal of the American Chemical Society 49, 2061-2064 (1927); Kondamudi, N.; Mohapatra, S. K.; Misra, M. Journal of Agricultural and Food Chemistry 56 (24), 11757-11760 (2008); Scanlan, J. U.S. Pat. No. 6,488,732 (2002); Martin, M. J. et al., Talanta, 54, 291-297 (2001); Misra, M.; Mohapatra, S. K.; Kondamudi, N. V. US 2010/0287823; Couto, R. M.; Fernandes, J.; Gomes da Silva, M. D. R.; Simoes, P. C. J. Supercritical Fluids, 51(2), 159-166 (2009); Oliveira, L. S.; Franca, A. S.; Camargos, and Ferraz, V. P. Bioresource Technology 99, 3244-3250 (2008); Abdullah, M.; Bulent Koc, A. Renewable Energy 50, 965-970 (2013); Al-Hamamre, Z.; Foerster, S.; Hartmann, F.; Kroger, M.; Kaltschmitt, M. Fuel, 96, 70-76 (2012); Khan, N. A.; Brown, J. B. Journal of the American Oil Chemists' Society, 30, 606-609 (1953); Seung-H. Yoo, Young-Wun Kim, Kunwoo Chung, Seung-Yeop Baik, Joon-Seop Kim. Corrosion Science, 59, 42-54 (2012); Rivera-Grau, L. M.; Casales, M.; Regla I.; Ortega-Toledo, D. M.; Ascencio-Gutierrez, J. A.; Gonzalez-Rodriguez, J. G.; Martinez-Gomez, L. International Journal of Electrochemical Science, 7, 12391-12403 (2012); Erik M. Quandt, Michael J. Hammerling, Ryan M. Summers, Peter B. Otoupal, Ben Slater, Razan N. Alnahhas, Aurko Dasgupta, James L. Bachman, Mani V. Subramanian, and Jeffrey E. Barrick, ACS Synth. Biol., Mar. 8, 2013; Williams C F, McLain J E, J Environ Qual. 2012 September-October; 41(5): 1473-80.
Amongst the patents reviewed to sustain the originality of the invention, patent JP2013013344 introduces a method for production of coffee oil for aromatic applications, where oil is extracted from roasted coffee beans hydrated with an oil/water emulsion using a centrifuge. This patent does not mention using the linoleic acid contained in the triglycerides present in the oil that has been extracted from coffee to obtain imidazolines, whose main quality is high adherence to metallic structures.
The patent with registration number CN 102875160 A introduces an invention related to the production of ceramic compound based additives using microwave radiation induction processes, hydroxymethylation and esterification where the raw materials are the lignosulphonates extracted from ground coffee. This patent does not describe any process related to the production of coffee biodiesel and imidazolines, such as the process of transesterification with KOH catalyzed methanol and aminolysis with aminoethylethanolamine (AEEA) respectively.
The patent with registration number US2007/0259084 A1 is related to the extraction of coffee surfactants using sugar transesterification and coffee oil, whose porpoise is the production of emulsions of this organic compound to improve coffee products, such as instant coffee, improving its aroma and taste. Likewise, this patent does not contemplate the use of coffee oil nor the processes inherent to extracting imidazolines for their use as corrosion inhibitors in the hydrocarbon industry.
The patent with registration number AR2010P100096 20100115 introduces a method to obtain biodiesel from coffee grounds. The purpose of this invention is to recycle coffee residue to produce a renewable fuel, with low environmental impact, however it makes no reference about any method or process to use organic coffee residue to inhibit interior corrosion in pipelines, containers and other industrial facilities related to storage and transport of hydrocarbons.
The patent with registration number US 2010/0287823 A1 describes a method for the production of a biofuel using one or more sources of coffee as raw material, such as green coffee grains, roasted coffee grains, ground coffee or ground coffee byproducts. This biofuel is extracted using a transesterification procedure of the triglycerides found in the coffee sources mentioned above, where the products obtained can be used for other purposes such as the production of cosmetics, drugs, food or fuel materials, however this patent does not consider an aminoethylethanolamine aminolysis (AEEA) process for the production of imidazoline mixtures.
Other patents reviewed, contemplate the production of biofuels, patents U.S. Pat. No. 8,545,702 y U.S. Pat. No. 8,540,881 B1, which are related to the production of biodiesel and/or glycerin from various processes, such as oil transesterification. These patents do not consider the use of coffee residue, nor the extraction of its oil as raw material for the production of corrosion inhibitors.
Likewise, there are patents related to obtaining imidazolines and their byproducts from chemical processes for various applications, such as processing of imidazolines of polycarboxylic acids for production of cleaning products (U.S. Pat. No. 5,049,315) imidazolines (U.S. Pat. No. 2,161,938), process for the preparation of substituted imidazoline as a fabric softener for the textile industry (U.S. Pat. No. 5,154,841). However, none of these patents make reference to the processing of coffee residue and using the linoleic acid contained in the triglycerides of the oil extracted from coffee for the synthesis of 2-alkyl-1-hidroxiethyl imidazolines which is doubly unsaturated and its main feature is high adherence to metallic surfaces.